[Yashas]

You actually optimized the code with this

Код:

"%s%s", PATH, playername

Using the define directly is faster.

About the other suggestion>>
He already has a specifier(%s or %c or ...) so he doesn't need an %s at the end.He is mostly having an error with his define.

And why can't it be used directly?
#define PATH "/users/%s.ini"
format(string,sizeof(string),PATH,playername);